An ink jet printer is as an example of a printing apparatus that ejects droplets of ink onto a recording medium such as a sheet of paper, for printing an image on the recording medium. The ink jet printer includes a print engine having at least one ink jet head provided with an ink cartridge that accommodates the ink. In operation of the print engine, the ink is supplied from the ink cartridge to ejection nozzles within each ink jet head, so that a printing operation is performed by ejection of the ink droplets from selected ejection nozzles.
However, ink jet printers typically implement an uncompensated pressurized ink cartridge or positive pressure pump to supply ink to an ink reservoir or print head. This supply is typically provided without monitoring pressure or flow rate of the ink, or estimating the demand of ink prior to supply. These systems are demand based (e.g., supply ink after ink has been printed), and as a result, the ink supply system may falter, either due to insufficient ink flow, an oversupply of ink, or suffer from poor system response time.
Therefore, a method to predict ink usage and regulate ink flow accordingly in an ink jet printer is desired.